Illuminated push-button switch construction with safety set and reset mechanism



May 26, 1970 A. A. Dl PILLA 3,

ILLUMINATED PUSH-BUTTON SWITCH CONSTRUCTION WITH SAFETY SET AND RESET MECHANISM Filed Jan. 25, 1968 4 Sheets-Sheet 1 FIG-l I72 FIG-2 98 82 90 88 L" 3 I44 4 1 34 I46 36 H8 H8 H6 vI54 I52 I54 INVENTOR ANTHONY A. Di PILLA awn m H IS ATTORNEYS A. A. D! PILLA May 26, 1970 SET AND RESET MECHANISM 4 Sheets-Sheet 2 Filed Jan. 25, 1968 FIG-l6 FIG-3 FIG-4 INVENTOR ANTHONY A. DiPILLA HIS ATTORNEYS May 26, 1970 A. A. DI PILLA 3,514,

ILLUMINATED PUSH-BUTTON SWITCH CONSTRUCTION WITH SAFETY SET AND RESET MECHANISM Filed Jan. 25, 1968 4 Sheets-Sheet :s

F|G"5 FIG-6 I I 4 84 119% @Em 8 0 I 7e 7e )1 6 I46 3g 51 54 FIG-7 ill 70 5'; 5' I3 O I" L62 66 32 [55 I30 I54 I53 |53 FIG I4 I36 49 l6! 7, INVENTOR ANTHONY 'A. DiPILLA HIS ATTORNEYS 1970 A. A. DI PILLA 3,514,564

ILLUMINATED PUSH-BUTTON SWITCH CONSTRUCTION WITH SAFETY SET AND RESET MECHANISM Filed Jan. 25, 1968 4 Sheets-Sheet 4.

FIG-8 FIG-9 'llic INVENTOR ANTHONY A. DiPILLA BY 44 I M 421% HIS ATTORNEYS United States Patent Office 3,514,564 Patented May 26, 1970 3,514,564 ILLUMINATED PUSH-BUTTON SWITCH CON- STRUCTION WITH SAFETY SET AND RESET MECHANISM Anthony A. DiPilla, Philadelphia, Pa., assignor t Robertshaw Controls Company, Richmond, Va., a corporation of Delaware Filed Jan. 25, 1968, Ser. No. 700,622 Int. Cl. H01h 9/18 US. Cl. 200-167 35 Claims ABSTRACT OF THE DISCLOSURE There is disclosed an illuminated pushbutton switch construction having a tubular casing that receives a pushbutton means at the upper casing end and has a lower switch means at the lower casing end. The push-button means is movable inward into the upper casing end by an initial pushing in action and thereafter movable upwardly by a release counterspring action. This places the push-button means in operable locked condition to operate the switch means as often as desired. The pushbutton means may be removed from the casing by an upward, outward movement, followed by an inward, downward pushing action of the push-button means. Thereafter, the push-button means may be removed from the casing by an upward and outward removing action completely to remove the push button from the casing. The push button is prevented from actuating the switch means during the initial introduction of the push-button means into the casing, and the push button can only operate the switch means after it has been released from the first pushing in action.

One of the features of this invention includes a construction in which a push button is introduced into the upper end of an axially directed casing and is then released to place the push-button means in operable locked condition to operate a switch means at the lower end of the casing.

Another feature of this invention includes a construction in which the push-button means cannot operate a switch means during the first or initial introduction of the push-button means into the casing and can operate the switch means as often as desired after the push-button means has been released from the first or initial pushed in position.

Another feature of this invention includes a construction in which a lens holder means is connected to a light holder means by a connecting and moving frame means which operates a locking spring means, to lock and release the push-button means in and from the casing.

Another feature of this invention includes a locking spring means which can be made from a spring wire member.

Another feature of this invention includes a construction in which a plunger is provided at the lower end of the casing to actuate the switch means.

Other features of this invention are apparent from this description, the appended claimed subject matter, and/or from the accompanying drawings, in which:

FIG. 1 is an exploded perspective view of an embodiment of this invention including a casing with one form of a switch at one end of the casing and with a pushbutton means outside the other end of the casing.

FIG. 2 is a vertical cross section of FIG. 1 taken along the line 2-2 of FIG. 1.

FIG. 3 is a transverse vertical view of FIG. 2, taken on the line 3 -3 of FIG. 2.

FIG. 4 is a view similar to FIG. 2, but showing the push-button means partially inserted in the casing.

FIG. 5 is a view similar to FIG. 4, but showing the push-button means further pushed in by an initial pushing in action, that does not actuate a plunger to switch actuating position.

FIG. 6 is a view similar to FIG. 5 but showing the push-button means moved slightly outward from the position of FIG. 5, by released counter action, in a manner to place the push-button means in operable locked condition.

FIG. 7 is a view similar to FIG. 6, and showing the push-button means pushed in from the position of FIG. 6 to a position where the plunger actuates the switch attached to the end of the casing.

FIG. 8 is a view similar to FIG. 6 and showing the push-button means subjected to an initial pulling out action upward preparatory to releasing the push-button means from the casing.

FIG. 9 is a view similar to FIG. 8, but showing the push-button means pushed in from the position of FIG. 8 to perform the second step in releasing the push button from the casing.

FIG. 10 is a view similar to FIG. 9, but showing the push button moved outwardly from the position of FIG. 9 by a released counter action, which permits the pushbutton means to be removed outwardly from the casing.

FIG. 11 is an exploded perspective view of the plunger actuating center member or safety cam.

FIG. 12 is a cross section taken along the line 12-12 of FIG. 11.

FIG. 13 is a diagrammatic upward view along line 1313 of FIG. 7.

FIG. 14 is a broken cross section along line 14--14 of FIG. 13.

FIGS. 15 and 16 show a clip member.

Certain words, which indicate direction, relative position, and the like, are sometimes used in this specification and in the claimed subject matter for the sake of brevity and clearness. However, it is to be understood that these words are used only in connection with the views in the drawings, and that in actual use the parts so described may have entirely different direction, relative position, and the like. Examples of such words are vertical, horizontal, upper, lower, etc.

\ An embodiment of this invention may include an axially directed casing 20 which may be a tubular casing. The casing 20 may be an upper push-button means receiving first casing end 22 and a lower switch means receiving second casing end 24. A push-button means 26 is movable inward relatively to said first casing end 22 by an initial pushing in action, such as shown sequentially in FIGS. 4 and 5, and thereafter movable upwardly relative to said first casing end 22 by released counter action, or spring action, as shown sequentially in FIG. 6 with relation to FIG. 5 to place said push-button means in operable locked condition so that said push-button means 26 may thereafter be repeatedly pushed in to the position of FIG. 7 and released to the position of FIG. 6 to operate switch means 28 at the lower end 24 of the casing 20.

The push-button means 26 may be released and removed from the locked operable condition of FIGS. 6 and 7 by an initial pulling out action on said push-button means, as shown in FIG. 8, followed by a pushing in action on said push-button means 26, as shown in FIG. 9. Thereafter the push-button means 26 may be released and removed from the casing 20 as illustrated in FIGS. 10 and 2.

If desired the release and removal of the push-button means from the casing 20 may include an upward and outward released counter action, or counter spring action, produced from the position of FIG. 9 to the position of FIG. 10. This may include the counter spring action of the compression springs 30 of the lower lamp energizing contacts 3-2, and the counter spring action of the compression spring 34 of the plunger 36.

Switch means may be provided at the second casing end 24. Under certain conditions such means may be considered to be the lamp energizing contacts 32 and 38. Under certain other conditions, such switch means may be considered to be the plunger actuator actuatable switch means 28, which is secured to the second casing end 24, by means of bracket 40. Such plunger actuatable switch means 28 may have a switch actuator rod 42 which may be moved inward and outward to place the switch means 28 in actuated or unactuated condition, as is well known. Such actuator rod 42 may be movable into the switch 28 to place the switch 28 in actuated condition, as shown in FIG. 7, and may be released to move outwardly, to place the switch 28 in unactuated condition, as shown in FIG. 6.

The switch actuator rod 42 may be moved down to actuated condition of FIG. 7, or to unactuated condition as shown in FIG. 6 and other figures, by the upwardly spring biased plunger 36.

The construction is such that the push button means 26 operates locking means, to be described, to lock said push-button means 26 in operable locked condition, as shown in FIG. 6, by an initial pushing in action, as shown in FIG. 5, followed by a released counter action or spring action which moves the push-button means 26 to the operable position shown in FIG. 6.

When the push button 26 is in the operable condition shown in FIG. 6, it may be repeatedly operated or pushed in, to the position of FIG. 7, to cause the plunger 36 to move down and engage the switch actuator rod 42, to place the switch 28 in actuated condition. Thereafter, the push-button means 26 may be repeatedly released to return by released counter action or spring action to the position of FIG. 6 which places the switch 28 in unactuated condition because of the upward movement of the plunger 36 away from the rod 42. Thus push-button means 26 may be repeatedly moved downwardly to the position of FIG. 7 and be released to move upwardly to the position of FIG. 6 as many times as desired.

The push-button means 26 may be removed from the casing 26 by performing the operations sequentially shown in FIGS. 8, 9, 10, and 2. The push button means is first pulled out to the position of FIG. 8, and such movement starts a push-button means releasing means so that the push button 26 will beeventually removed from the casing 20 by sequentially following the steps of FIGS. 8, 9, 10, and 2. Thus, after the push-button means has been pulled out to the position of FIG. 8, it is then push in to the position of FIG. 9 and released. This may be followed by a released action of FIG. 10, where the push-button means 26 is released and is moved upwardly by counter action, such as by counter spring action produced for example first by the combined spring action of springs 30 and 34 followed by the single spring action of the spring 34 as more fully to be described.

When the push-button means 26 is initially pushed in to lock the push-button means 26 in the operating or operable condition of FIG. 6, as shown in the sequential positions of FIGS. 16, the plunger 36 is prevented from actuating the switch means 28 and its actuating rod 42. The downward travel of the plunger 36 is arrested, as shown in FIG. 5, so that the plunger lower end 44 can not travel downwardly below the lower line 47 of the two datum plane lines 47 and 49, so that the plunger cannot accidentally actuate the switch means 28.

However, after the push-button means is released to the position of FIG. '6 so that the push-button means 26 is in operating or operable condition, the plunger 36 is permitted to operate the switch means 28 to actuated condition, as shown in FIG. 7, when the push-button means is again pushed down.

Thereafter, if the push-button means 26 is released to return to the condition of FIG. 6, the switch means 28 also returns to unactuated condition because the plunger end 44 rises above and out of contact with the uppermost position of actuating rod 42.

During any subsequent pushing in and releasing actions of the push-button means 26 between the positions of FIGS. 6 and 7 the plunger 36 is permitted to operate the switch means 28 to actuated and unactuated conditions as often as desired. This can continue until the pushbutton means 26 is removed by the sequential operations illustrated in FIGS. '8, '9, 10, and 2, as elsewhere described.

The details by which the above operations and actions are achieved will now be described.

'I HE PUSH-BUTTON CONSTRUCTION MEANS The push-button means or push-button construction means 26 may include a lamp holder means 46 and a pushing member means or lens holder means 48 relatively movably connected together by a connecting and moving frame means 50 which imparts relative movements between the lamp holder means, the lens holder means, and other parts of the embodiment.

THE LAMP HOLDER MEANS The lamp holder means 46 includes an upper plate-like section 52 and a lower plate-like section 54 which may be made of electrical insulating material and which may be permanently secured together during the assembly of the parts, as is apparent from other descriptions in this disclosure.

A plurality of electrically energized flange base lamps 56 may be removably mounted in the resilient insulating section 54 of the lamp holder means 46. The lamps 56 may have lamp flanges 57 which carry the upper lamp energizing contacts 38 which are relatively permanently frictionally mounted in the lamp holder 46. The lamps 56 may emit differently colored light to or through the lens holder means 48. The mounting and construction of such lamps 56, flanges 57 and contacts 38 form, of themselves, no part of this invention. They are now well known in connection with this type of embodiment and are therefore not further described in detail herein. These lamps 56, flanges 57 and contacts 38 move in unison with the lamp holder means 46. The lamps 56 may be removed downwardly from the section 54. If desired, the upper platelike section 52 may have means to hold colored flexible light filters over the lamps 56 in a manner now well known. The filters may be removable upwardly from the section 52, while the flange based lamps 56 may be removable from the bottom of section 54, in a manner now well known.

The lamp holder means 46 also has a locking spring means 58 which may be made from two resilient wire members. Each wire member may be bent into a pair of downward U-shaped legs 60 connected together by a horizontal spring member 62. The legs 60 may also be respectively connected to downwardly directed inverted L-shaped wire ends 64 which are locked between the joining surfaces of sections 52 and 54 and are also held in grooves 66 in the lower section 54.

The legs 60 and the horizontal spring member 62 are resiliently horizontally movable together and have the normal unbiased position shown in FIG. 2 with the mem ber 62 and the double slant portions 67 of the legs 60 extending horizontally out beyond the inner surface line 68, FIG. 2, of the casing 20. Such horizontal member 62 and the double slant portions 67 are moved inwardly when the push button means 26 is pushed into the casing 20 as shown in other figures of the drawings.

The lamp holder means 46 also has a safety cam means 70, FIGS. 2, 11 and 12, which is located in a horizontal cam slot 72 in the lower section 54 of the lamp holder means 46. The slot 72 is covered by the upper section 52. The safety cam means 70 is used as part of the means for preventing the plunger 36 from actuating the switch means 28, as in FIG. 5, and as part of the means permitting the plunger 36 to operate the switch means 28, as in FIG. 7, as elsewhere more fully described.

The lamp holder means 46 also has outer openings 74 to receive and allow passage of outer connecting and moving frame members 76 for engagement with and actuation of the locking spring means horizontal member 62, etc. Such lamp holder means also has a central opening 78 to receive and allow passage of an inner connecting and moving frame member 80 which is part of the means for preventing the plunger 36 from actuating the switch means 28, as in FIG. 5, and as part of the means for permitting the plunger 36 to operate the switch means 28, as in FIG. 7, as elsewhere more fully described.

THE LENS HOLDER MEANS AND CONECTING AND MOVING FRAME MEANS The lens holder means 48 is the pushing in and removing element of the pushbutton means 26. The connecting and moving frame means 50 connects and moves the lamp holder means 46 into and out of the casing 20, in response to the movement of the lens holder means 48 and other parts of the embodiment, as shown in the various figures of the drawings.

The lens holder means 48 includes a lens holder box 82 which may be locked and supported by the offset shoulders 84 on the outer frame members 76. Also, lens holder walls 86 may be carried by or be formed as enlargements of the outer frame members 76.

A colored lens 88 and a top lens 90 may be held by the lens holder means 48.

The colored lens 88 may rest on a recessed ledge 92 which is formed in opposite walls of the lens box 82. The colored lens 88 may be rectangular to fit closely adjacent the inner surfaces of the lens box 82 with opposite protrusions to fit in the ledge 92. Alternatively, the vertical edges 94 of the recessed ledge 92 may be extensions of the inner surfaces of the opposite walls 96 of the box 82, and the colored lens 88 may be rectangular with two edges engaging the enlargement walls 86 and two other edges engaging the inner surfaces of opposite walls 96.

The top lens 90 may be rectangular with two wedgeshaped protrusions 98 locked in openings 100 in the enlargement walls 86.

The central or inner connecting and moving frame member 80 may be generally T-shaped, as seen in FIG. 2, with the ends of the horizontal part 102, flanged members 104, connected to outer frame members 76 so that the frame member 80 is carried by the outer frame members 76.

The central frame member 80 has a vertical flange 106 and an offset shoulder 108 which engages and disengages a lug or shoulder 110 on the safety cam means 70, FIGS. 2, 11 and 12 to produce the switch means 28 actuating action by plunger 36 in FIG. 7 and the switch means 28 nonactuating action by the plunger 36 in FIG. 5, as more fully elsewhere described.

THE CASING AND TERMINAL BLOCK The casing may be a tubular metal casing which may be of rectangular or square cross section. Switch retaining clip means 112 at the bottom of casing 20 may include a plate 114, FIGS. 3 and 4, which is riveted to the inward casing flanges 116 by rivets 118. The plate 114 has a downward hook 120 and a downward resilient spring latch 122 to receive and secure the upper plate 124 of bracket 40 of the switch means 28.

A pair of lugs 126, FIG. 4, are also riveted to the flanges 116 and hold a plunger guiding ring 128 to receiver the lower end of the plunger 36.

Square rods 131 may be initially welded to the sides of the casing 20 to preliminarily receive and locate a terminal block 130 of insulating material in the casing 20. The terminal block 130 is then secured in fixed position in casing 20 in any suitable manner, such as by tabs (not shown) above the rods 131 forming a part of the casing 20. Each tab is bent inwardly and received above a shoulder (not shown) formed in the block The terminal block 130 carries upwardly biased terminal members or pins 132 which carry the lamp contacts 32 and are upwardly biased by compression springs 30. The upward travel of the terminal members 132 pass through rings 138 forming a part of terminal attaching clips 136 which extend upwardly through block 130. The rings 138 receive the lower ends of the springs 30 to electrically connect the terminal members 132 with the contacts 32.

The plunger 36 passes through the terminal block 130 and is upwardly biased by the compression spring which extends from the upper surface of lower flange 140 of spring receiving opening 142 to the upper plunger flange 144. A ring 145 is fixed near the lower end of the plunger 36. The upward travel of plunger 36 is limited by the ring 145 on plunger 36 engaging the lower surface of lower flange 140.

Stops 146 are formed in the casing 20 by forming openings 148 and bending the flanged stops 146 with their upper slanting surfaces 150.

The switch means 28 may be any well known plunger operated switch having terminal connectors 152 to be connected into any desired circuit to be controlled by the switch means 28 by operation of actuating rod 42. The body of switch means 28 may be secured to the bracket 40 by any suitable fasteners 154.

A neutral connection for the lamps 56 is shown in FIGS. 13 and 14 which is applicable to all of the figures. However, other neutral connections may be used if desired.

A neutral connection metal plate 151 may be countersunk in the lower lamp base section 54, which plate 151 may surround opening 155 of the plate 151. The plate 151 may have branches 149 extending into notches 153 of the lamp openings 159 in the lamp base sections 52 and 54. The branches 149 have resilient upward neutral tongue contacts 161 which engage the usual neutral cylindrical metal sleeves 147 of the lamps 56.

One or more upwardly biased neutral contacts 32A may be supported on the supporting base 130 of the casing. These contacts 32A may each have an upward contact pin to engage the neutral plate 151 to provide illuminating contacts for the lamps 56 in combination with the live flange contacts 38. These contacts 32A may be generally the same in construction and action as the contacts 32. The neutral contacts 32A have not been illustrated in the other figures, since their addition in such figures would have an overcrowding effect.

OPERATION The push-button means or push-button construction means 26, in the condition of FIGS. l-3, is moved downwardly to and past the position of FIG. 4. As the pushbutton means 26 is pushed down from the position of FIG. 4, the legs 60 temporarily arrest the downward movement of the lamp holder means 46 past the upper edge of opening 22 of the casing 20. The lens holder means 48 continues to move downwardly moving central frame member 80 downwardly causing shoulder 108 to engage lug 110 of safety cam means 70. The outer frame members 76 move downwardly at the same time so that their lower bent portions 156 move centrally of the horizontal members 62 of the spring means 58. The lamp holder means 48 and lens holder means 46 then move downwardly together to the position shown in FIG. 5.

When the push-button means 26 has been pushed down to the position of FIG. 5, the shoulder 108 of central frame member 80 prevents the cam 70 from rotating clockwise causing the cam arms 158 to act on the plunger 36. This has caused the horizontal bridge member 157 of the plate-like section 52 of lamp holder means 46 to engage the stops or stop members 146 of casing 20.

This has stopped downward movement of the lamp holder means 46. The horizontal spring members 62 have moved inwardly around the stops 146 by engagement with the slanting surfaces 150. Such spring members or means 62 have then sprung outwardly by their outward spring bias below the stops 146 to lock and arrest substantial upward movement of the lamp holder means 46 when the lens holder means 48 is released by the operator for upward movement of the lens holder means to the position of FIG. 6.

Also during the downward pushing action from FIG. 4 to FIG. 5, the plunger 36 has been pushed down by the cam arms 158 of the safety cam means 70 so that the lower end 44 of the plunger 36 is stopped at datum line 47 out of actuating switch contact with switch rod 42. The plunger spring has been further compressed. If it is desired to have slight contact between the plungers 36 and 42 at this time the movement of plunger 42 should be insufficient to actuate switch means 28 to actuated condition.

Also, during the downward movement from FIG. 4 to FIG. 5, the lower energizing lamp contacts 32 have been pushed down by the upper lamp contacts 38 and the springs 30 have been further compressed.

After the parts have been pushed down by the downward movement between FIGS. 4 and 5, the operator releases the lens holder means 48 so that there is a limited upward movement of some of the parts to the positions of FIG. 6. The lamp holder means 46 remains locked in FIG. 6. From these positions of FIG. 6 the lens holder means 48 may be repeatedly pushed down to the position of FIG. 7 repeatedly to actuate and deactuate the switch rod 44 and the switch means 28.

When the operator releases the lens holder means from the positions of FIG. to the positions of FIG. 6, the lens holder means 48 and the lamp holder means 46 move up by the reaction of plunger compression spring 34 and contact compression springs 30. The lamp holder means 46 is arrested in its upward travel by engagement of horizontal members 62 with the lower surface of stops 146.

The lens holder means 48 continues to rise slightly due to the upward force applied to the cam arms 158 by the plunger compression spring 34 via the plunger 36. This further movement of the lens holder means 48 is limited by engagement of the upper plunger flange 144 with the lower surface of the lamp holder means 46. The safety cam 70 is rotated clockwise about the pivot portion 160 and into opening 72 against the action of compression spring 166 removing the lug 110 of cam 70 from engagement with the shoulder 108 of central frame member 80. During this pivot action of cam 70 about pivot portion 160, which is received in a groove in the lower section 54 of the lamp holder means 46, the curved surfaces 162 of cam arms 158 move along the lower surface 164 of plate section 52 of the lamp holder means 46. The lower end of spring 166 rests on a lug 168 at the bottom of opening 72 and the upper end of spring 166 is held by lug 170 on cam 70.

It is apparent that the lower end of frame member 80 will be out of engagement with the plunger 36 at the time lug 110 moves away from engagement with the shoulder 108 of member 80. This additional movement of the lens holder means 48 causes the bent portions 156 of the outer frame members 76 to engage the horizontal members 62 deflecting the outer frame members 76 a slight amount. This creates a force tending to move the lens holder means 48 toward the plunger 36. This force comes into play as the lug 110 is pivoted out of engagement with shoulder 108 to cause the lens holder means 48 to move toward the plunger 36. The shoulder 108 of frame member 80 is then positioned relative to the cam 70 so that movement of the plunger 36 toward the lower end 24 of the casing 20 in response to movement of the frame member 80 does not permit the cam 70 to rotate counterclockwise to permit the lug 110 of the cam 70 to be engaged by the shoulder 108 of member 80. When the plunger 36 is moved away from the cam 70, the cam 70 is urged counterclockwise by the spring 166 causing the lug 110 to be placed in sliding engagement with the edge of member about the shoulder 108.

The lens holder means 48, FIG. 6, is therefore held in readiness to be repeatedly pushed down and released between the positions of FIGS. 6 and 7.

When the lens holder 48 is pushed down, as in FIG. 7, such lens holder 48 and plunger 36 are no longer arrested, as in FIG. 5, but are allowed to continue down to actuate the switch plunger rod 42 because the safety cam 70, in the position of FIG. 6, no longer can arrest the shoulder 108 of frame member 80. This permits the frame member 80 to push down the plunger 36 to the switch means 28 actuating position of FIG. 7. During this time the lamp holder means 48, and its sections 52 and 54, are held in the position of FIGS. 6 and 7 by the compression springs 30 and lamp contacts 32 and 38 and by the horizontal members 62 and stop lugs 146.

Removal of the push button means 26 from the casing 20 is accomplished by the sequences shown in FIGS. 8, 9 and 10.

The lens holder means 48 of the push button means 26 is first pulled upwardly and outwardly to the piston of FIG. 8 from a previous position of FIG. 6. If desired, suitable fingernail grooves 172, FIG. 2, or the like may be provided in lens for initial pulling out action. The upward pulling action is limited by the lower bent portions 156 of the outer frame member 76 acting on the upper horizontal bridge members of the arrested lamp holder means 48. Then the lens holder means 48 is then pushed downwardly to the position of FIG. 9. This downward movement is arrested by the stops or stop lugs 174 of frame members 76 which engage the horizontal members 62. The members 62 are arrested in their slight downward travel when the upper section 52 of the lamp holder means 46 engages the stops or stop lugs 146, as previously described. The stop lugs 174 are positioned on the frame members 76 so this downward movement of the lens holder means 48 is not sufficient to cause the plunger 36 to be moved a distance great enough to actuate the switch 28. Upon removal of the force providing this downward movement the lens holder means 48 with the lamp holder means 46 are released from its locking relationship with the casing 20 and can be pulled upwardly out of casing 20, as shown in FIG. 10.

This removal action of FIGS. 8, 9 and 10 is accomplished because when the lens holder means 48 is initially pulled up, as in FIG. 8, the lower bent portion 156 of the frame member 76 is withdrawn from its inward position relative to horizontal member 62 of FIG. 6. Then when lens holder 48 is pushed down, as in FIG. 9, the bent portion 156 moves outwardly of horizontal member 62. The locking spring means 58 are flexed inwardly as the stop lugs 174 are moved into engagement with the horizontal members 62 positioning the horizontal members 62 sothey clear the stop lugs 146 upon subsequent upward movement of the lamp holder means 46.

The subsequent upward movement of the lamp holder means 48 occurs when the force causing the downward movement is removed allowing the upward reaction force of plunger compression spring 34 and upward pushing action of plunger 36 on the lower section 54 of the lamp holder means 46 together with the spring action of springs 30 to position the horizontal members 62 above the stop lugs 146. Additionally, the spring action of spring 166 causes cam 70 to rock counterclockwise and cause cam arms 158 to further urge upward movement of the lamp holder means '46 along with the lens holder means 48. It will be noted that the inward flexure of the horizontal members 62 provides reaction forces which act on the bent portions 156 of the frame members 76 as the lamp holder means 46 and lens holder 48 are moved upwardly to cause a slight separation movement of the lamp holder means 46 and the lens holder means 48 as shown in FIG. 10.

The entire push-button means 26 can thereafter be removed from the casing 2-0 to the position of FIGS. 1 and 2. Thus, upon removal from the casing 20 the lens holder means 48 and the lamp holder means 46 are positioned relative to one another so they can be again inserted in the casing without any special positioning of the parts by the user.

The illuminated push-button switch construction which 'has been described can be readily altered to provide a construction in which the safety feature provided by the cam 70 arrangement is not present and still have an operable unit. Thus, it would only be necessary to elirninate the cam 70 and spring 166 during the assembly. It is thus apparent that the arrangement disclosed to provide for the locking and unlocking of the lamp holder means 46 in the casing 20 has utility independent of the safety feature provided by the cam 70 functions.

The construction described can also be modified in several ways to provide a unit where lamp indication is the only feature to be used, i.e., the lens holder means 48 cannot be pushed significantly inward of the casing 20 when the unit is mounted and therefore cannot be used to actuate a switch mounted atone end of the unit. As a lamp indication unit it merely serves to show which of the lamps 56 are energized from time to time.

In order that a lamp indication unit can be made from the push-button switch construction it is necessary that any modification allow the unit to be locked in place in the casing 20 and allow it to be released in the manner that has been described. In addition, the modification must prevent significant inward motion of the lens holding means 48 inwardly of the casing 20 after the unit is mounted in the casing. In the modification to be discussed the movement of the lens holding means 48 in- 'wardly of the casing 20 after the unit is locked in the casing 20 is the movement from the position shown in FIG. 6 and that shown in FIG. 5.

The preferred modification involves the use of at least one stop member 180, FIGS. 5, 16 and 17, which can be in the form of a two pronged clip member, with prongs 182 and 184, that are readily slipped in place on one or both of the frame members 76 above the lamp holder means 46. The clip member may be made of plastic material with the prong 184 having a slidable slanting surface 186 and a locking shoulder 188 to lock the clip member 180 on the frame member 76. The frame member 7'6 can slide relative to the clip so that the lamp holder means .46 and lens holder means 48 can be installed and removed from the casing 20 as previously described. The width of the stop member is such as to permit the lens holder means 48 to be moved toward the lamp holder means 46 only as far as the position shown in FIG. 5. Removal of the stop members can be accomplished by spreading the prongs 182 and 184 without the use of any special tools allowing the purchaser of a unit to have the option of using it as an illuminated push-button switch unit or as a lamp indication unit. This modification is also applicable to a unit which does not have the safety set and reset mechanism provided by the cam 70 and its cooperation with the lens mounting means 48.

In the above, FIG. 15 is a top view of the clip memher and FIG. 16 is a side view of FIG. 15 taken along the line 16-16 of FIG. 15.

Another possible modification for obtaining a lamp indication unit requires the removal of the function provided by the plunger 36, spring 34 and retainer ring 145. This, of course, may be accomplished by physical removal of the parts from the combination. With such an arrangement the lens holder means 48 and lamp holder means 46 can be locked in position in the casing as shown in FIG. 6, but with the cam 70 in position as shown in 'FIG. 5 since the plunger 36 is not present to rotate the cam 70 clockwise during the insertion operation. It is obvious that the cam 70 is then merely serving as a stop member to limit the inward movement of the lens holding means 48 during insertion of the lamp holder means 46 and the lens holding means 48. Since it is not rotated clockwise out of the stop position upon completion of the insertion phase, it serves as a stop member should anyone subsequently push on the lens holder means 48. It is therefore possible to use a nonrotatable element in place of the cam 70 and spring 72 when a lamp indication unit is to be manufactured. Such an arrangement would allow the lamp indication unit to be mounted in a casing 20 even though the casing 20 carried the usual plunger 36 arrangement.

It is thus to be seen that a new, useful and unobvious illuminated push-button switch construction with or without safety set and reset mechanism has been provided by this invention.

What is claimed is:

1. In combination:

a casing having a receiving casing aperture means;

switch means connected with said casing;

push button construction means disposed in said aperture means to actuate and unactuate said switch means by actuating means of said push-button construction means being operatively associated with said switch means when said push-button construction means is disposed in a locked condition in said aperture means and being movable inward relatively to said aperture means by a pushing in action;

locking and withdrawing means carried by said casing and said push-button construction means to lock said push-button construction means in said switch means actuating and unactuating operable locked condition by an initial locking pushing in action of said push-button construction means into said aperture means followed by a release of said pushbutton construction means, and to withdraw said push-button construction means from said operable locked condition by an initial pulling out action of said push-button construction means followed by a releasing pushing in action of said push-button construction means, said push-button construction means being inwardly actuatable and outwardly releasable to operate said switch means respectively to actuated switch means condition and to unactuated switch means condition while said push-button construction means is in said locked operable condition;

and safety means carried by said push-button construction .means and operatively associated with said actuating means to prevent said push-button construction means from operating said switch means to actuated condition during said initial locking pushing in action; and a switch means operating plunger movably carried by said casing to operatively associate said actuating means to said switch means when said push-button construction means is in said locked condition.

2. In combination:

a casing having a receiving casing aperture means;

switch means connected with said casing;

a push-button construction means disposed in said aperture means to actuate and unactuate switch means by actuating means of said push-button construction means being operatively associated with said switch means when said push-button construc tion means is disposed in a locked condition in said aperture means and being movable inward relatively to said aperture means by a pushing in action;

locking and withdrawing means carried by said casing and said push-button construction means to lock said push-button construction means in said switch means actuating and unactuating operable locked condition by an initial locking pushing in action of said push-button construction means into said aperture means followed by a release of said push-button construction means, and to withdraw said push-button construction means from said operable locked condition by an initial pulling out action of said pushbutton construction means followed by a releasing pushing in action of said push-button construction means, said push-button construction means being inwardly actuatable and outwardly releasable to operate said switch means respectively to actuated switch means condition and to unactuated switch means condition while said push-button construction means is in said locked operable condition;

and safety means carried by said push-button construction means and operatively associated with said actuating means to prevent said push-button construction means from operating said switch means to actuated condition during said initial locking pushing in action; and a switch means operating plunger movably carried by said casing to operatively associate said actuating means to said switch means when said push-button construction means is in said locked condition,

a second safety means carried by said push-button construction means and limiting movement of said pushbutton construction means during said releasing pushing in action of said push-button construction means to prevent said push-button construction means from operating said switch means to actuated condition during said releasing pushing in action of said push-button construction means.

3. A combination according to claim 1 in which said push-button construction means includes a pushing member means and a lamp holder means relatively movably and unitarily secured together, and in which said lamp holder means is locked to said casing by an initial locking pushing in action of said pushing member means followed by a release of said pushing member means, and in which said pushing member means comprises said actuating means and being pushable into and releasable out respectively to actuate and to unactuate said switch means while said lamp holder means is locked to said casing, and said safety means prevents said pushing member means from actuating said switch means to actuated condition during said initial pushing in action of said pushing member means.

4. A combination according to claim 3 in which said lamp holder means is unlocked from said casing by a pulling out action of said pushing member means followed by a releasing pushing in action of said pushing member means.

5. In combination:

a casing having a receiving casing aperture means;

switch means connected with said casing;

push-button construction means disposed in said aperture means to actuate and unactuate said switch means by actuating means of said push-button construction means being operatively associated with said switch means when said push-button construction means is disposed in a locked condition in said aperture means and being movable inward relatively to said aperture means by a pushing in action;

locking and withdrawing means carried by said casing and said push-button construction means to lock said push-button construction means in said switch means actuating and unactuating operable locked condition by an initial locking pushing in action of said pushbutton construction means into said aperture means followed by a release of said push-button construction means, and to withdraw said push-button construction means from said operable locked condition by an initial pulling out action of said push-button construction means followed by a releasing pushing in action of said push-button construction means, said push-button construction means being inwardly actuatable and outwardly releasable to operate said switch means respectively to actuated siwtch means condition and to unactuated switch means condition while said push-button construction means is in said locked operable condition;

and safety means carried by said push-button construction means and operatively associated with said actuating means to prevent said push-button construction means from operating said switch means to actuated condition during said initial locking pushing in action; and a switch means operating plunger movably carried by said casing to operatively associate said actuating means to said switch means when said push-button construction means is in said locked condition,

said push-button construction means including a pushing member means and a lamp holder means relatively movably and unitarily secured together, said lamp holder means being locked to said casing by an initial locking pushing in action of said pushing member means followed by a release of said pushing member means, said pushing member means comprising said actuator means and being pushable into and releasable out respectively to actuate and to unactuate said switch means while said lamp holder means is locked to said casing, said safety means preventing said pushing member means from actuating said switch means to actuated condition during said initial pushing in action of said pushing member means, said lamp holder means beng unlocked from said casing by a pulling out action of said pushing member means followed by a releasing pushing in action of said pushing member means,

said push-button construction means including a second safety means limiting movement of said pushing member means during said releasing pushing in action of said pushing member means to prevent said push member means from actuating said switch means to actuated condition during said releasing pushing in action of said pushing member means.

6. A combination according to claim 4 in which said pushing member means is a lens assembly means.

7. In combination:

tubular casing having a receiving casing aperture means adjacent one end and a plunger guiding means adjacent the other end;

switch means actuating plunger reciprocable in said plunger guiding means, said plunger being entirely carried by said casing;

switch means connected to said casing adjacent said other end and being actuatable by reciprocation of said plunger to a switch means actuated condition and a switch means unactuated condition;

pushing member means and a lamp holder means relatively movably unitarily secured together as a push-button construction means and being insertable in and removable from said casing through said aperture means, said push button construction means being disposed in said aperture means;

locking means carried by said casing and said pushbutton construction means to lock said lamp holder means in locked condition in said casing by an initial in action action of said pushing member means, followed by a releasing action of said pushing member means;

locking release means carried by said casing and said push-button construction means to release said lamp holder means from said locked condition by a pulling out action on said pushing member means followed by a releasing pushing in action of said pushing member means; plunger reciprocating means connected to said pushing member means to reciprocate said plunger to switch means actuated condition by inward pushing in action on said pushing member means and to reciprocate said plunger to switch means unactuated condition by release of said pushing member means while said lamp holder means is in locked condition; and safety means carried by said push-button construction means and operatively associated with said plunger reciprocating means to prevent said plunger reciprocating means from reciprocating said plunger to switch means actuated condition during said initial pushing in action of said pushing member means.

In combination: tubular casing having a receiving casing aperture means adjacent one end and a plunger guiding means adjacent the other end; switch means actuating plunger reciprocable in said plunger guiding means, said plunger being entirely carried by said casing; switch means connected to said casing adjacent said other end and being actuatable by reciprocation of said plunger to a switch means actuated condition and a switch means unactuated condition; pushing member means and a lamp holder means relatively movably unitarily secured together as a push-button construction means and being insertable in and removable from said casing through said aperture means, said push-button construction means being disposed in said aperture means;

locking means carried by said casing. and said pushbutton construction means to lock said lamp holder means in locked condition in said casing by an initial pushing in action of said pushing member means, followed by a releasing action of said pushing member means;

locking release means carried by said casing and said push-button construction means to release said lamp holder means from said locked condition by a pulling out action on said pushing member means followed by a releasing pushing in action of said pushing member means;

plunger reciprocating. means connected to said pushing member means to reciprocate said plunger to switch means actuated condition by inward pushing in action on said pushing member means and to reciprocate said plunger to switch means unactuated condition by release of said pushing member means while said lamp holder means is in locked condition;

and safety means carried by said push-button construction means and operatively associated with said plunger reciprocating means to prevent said plunger reciprocating means from reciprocating said plunger to switch means actuated condition during said initial pushing in action of said pushing. member means; said pushing member means including a second safety means limiting movement of said pushing member means during said releasing pushing in action of said pushing member means to prevent said pushing member means from actuating said switch means to actuated condition during said releasing pushing in action of said pushing member means.

9. A combination according to claim 8 in which said lamp holder means has outwardly biased spring members defining part of said locking means to lock said lamp holder means to said casing.

10. A combination according to claim 9 in which said casing has stop members defining part of said locking means to engage with said outwardly biased spring members to lock said lamp holder means to said casing.

11. A combination according to claim 10 in which said pushing member means has outer connecting and moving frame members defining part of said locking release means which inwardly hold said outwardly biased spring members to allow said outwardly biased spring members to pass upwardly past said stop members after said releasing pushing in action has been made on said pushing member means.

12. A combination according to claim 11 in which said second safety means includes a stop lug on said frame members positioned to engage said spring members during said releasing pushing in action on said pushing member means.

13. A combination according to claim 11 in which said outwardly biased spring members are each made from a single spring wire.

14. A combination according to claim 13 in which said single spring wire is bent to form a pair of downward U-shaped legs connected together by a horizontal spring member, said legs and horizontal spring member being resiliently horizontally movable together and having a normal unbiased position outwardly beyond said casing, said U-shaped legs having double slant portions which are moved inwardly when said lamp holder means is pushed into said casing, and in which said outer connecting frame members of said pushing member means are engageable with said horizontal spring members to allow said horizontal spring members to lock with said casing during said initial pushing in action of said pushing member means and to prevent said horizontal spring members from remaining locked to said casing during said releasing pushing in action of said pushing member means.

15. A combination according to claim 11 in which said plunger is upwardly biased and engages an inner frame member which is connected to said pushing member means to upwardly bias said pushing member means.

v16. A combination according to claim 15 in which said lamp holder means has a rockable safety cam means that defines part of said first-named safety means which is engaged by a shoulder on said inner frame member and which engages said plunger to limit the down-ward movement of said plunger by said pushing member means to prevent actuation of said switch means to actuated condition during said initial pushing in action of said pushing member means, and in which said safety cam means is biased out of engagement with said shoulder to permit said inner frame member to engage said plunger to push said plunger to switch means actuating condition when said lamp holder means is in locked condition.

17. In combination:

a tubular casing having a receiving casing aperture means adjacent one end;

a switch means actuating plunger reciprocable in said casing, said plunger being entirely carried by said casing;

a switch means connected to said casing and being ac tuatable by reciprocation of said plunger to a switch means actuatedcondition and a switch means unactuated condition; pushing member means and a lamp holder means relatively movably unitarily secured together as a push button construction means and being insertable in and removable from said casing through said casing aperture means, said switch means being actuatable to actuated condition and unactuated condition by pushing in action and release action on said pushing in member means, said push-button construction means being disposed in said aperture means; locking means carried by said casing and said pushbutton construction means to lock said lamp holder means in locked condition in said casing by an initial pushing in action of said pushing member means,

15 followed by a releasing action of said pushing mem ber means;

locking release means carried by said casing and said push-button construction means to release said lamp holder means from said locked condition by a pulling out action on said pushing member means followed by a releasing pushing in action of said pushing member means;

plunger reciprocating means connected to said pushing member means and operatively associated with said plunger to reciprocate said plunger to switch means actuated condition by inward pushing in action on said pushing member means and to reciprocate said plunger to switch means unactuated condition by release of said pushing member means while said lamp holder means is in locked condition;

and safety means carried by said push button construction means and operatively associated with said plunger reciprocating means to prevent said plunger reciprocating means from reciprocating said plunger to switch means actuated condition during said initial pushing in action of said pushing member means.

18. A combination according to claim 17 in which said lamp holder means has outwardly biased spring member means defining part of said locking means to lock said lamp holder means to said casing.

19. A combination according to claim 18 in which said casing has stop member means defining part of said locking means to engage with said outwardly biased spring member means to lock said lamp holder means to said casing.

20. In combination:

a tubular casing having a receiving casing aperture means adjacent one end;

a switch means actuating plunger reciprocable in said casing, said plunger being entirely carried by said casing;

a switch means connected to said casing and being actuatable by reciprocation of said plunger to a switch means actuated condition and a switch means unactuated condition;

a pushing member means and a lamp holder means relatively movably unitarily secured together as a push button construction means and being insertable in and removable from said casing through said casing aperture means, said switch means being actuatable to actuated condition and unactuated condition by pushing in action and release action on said pushing in member means, said push-button construction means being disposed in said aperture means;

locking means carried by said casing and said pushbutton construction means to lock said lamp holder means in locked condition in said casing by an initial pushing in action of said pushing member means, followed by a releasing action of said pushing member means;

locking release means carried by said casing and said push button construction means to release said lamp holder means from said locked condition by a pulling out action on said pushing member means followed by a releasing pushing in action of said pushing member means;

plunger reciprocating means connected to said pushing member means and operatively associated with said plunger to reciprocate said plunger to switch means actuated condition by inward pushing in action on said pushing member means and to reciprocate said plunger to switch means unactuated condition by release of said pushing member means while said lamp holder means is in locked condition;

and safety means carried by said push-button construction means and operatively associated with said plunger reciprocating means to prevent said plunger to switch means actuated condition during said initial pushing in action of said pushing member means;

said lamp holder means having outwardly biased spring member means defining part of said locking means to lock said lamp holder means to said casing;

said casing having stop member means defining part of said locking means to engage with said outwardly biased spring member means to lock said lamp holder means to said casing;

said pushing member means having outer connecting and moving frame member means defining part of said locking release means which inwardly hold said outwardly biased spring member means to allow said outwardly biased spring member means to pass upwardly past said stop member means after said releasing pushing in action has been made on said pushing member means.

21. A combination according to claim 20 in which said outwardly biased spring member means is made from a single spring wire.

22. A combination according to claim 21 in which said single spring wire is bent to form a pair of downward U-shaped legs connected together by a horizontal spring member, said legs and horizontal spring member being resiliently horizontally movable together and having a normal unbiased position outwardly beyond said casing, said U-shaped legs having double slant portions which are moved inwardly when said lamp holder means is pushed into said casing, and in which said outer connecting frame members of said pushing member means are engageable with said horizontal spring members to allow said horizontal spring members to lock with said casing during said initial pushing in action of said pushing member means and to prevent said horizontal spring members from remaining locked to said casing during said releasing pushing in action of said pushing member means.

23. A combination according to claim 22 in which said plunger is upwardly biased and engages an inner frame member which is connected to said pushing member means to upwardly bias said pushing member means.

24. A combination according to claim 23 in which said lamp holder means has a rockable safety cam means that defines part of said first-named safety means and which engages said plunger to limit the downward movement of said plunger by said pushing member means to prevent actuation of said switch means to actuated condition during said initial pushing in action of said pushing member means, and in which said safety cam means is biased out of engagement with said shoulder to permit said inner frame member to engage said plunger to push said plunger to switch means actuating condition when said lamp holder means is in locked condition.

25. In combination:

tubular casing having a receiving casing aperture means adjacent one end;

a lens holding means and a lamp holder means relatively movably unitarily secured together to define a push-button construction means and being insertable in and removable from said casing through said aperture means, said push-button construction means being disposed in said aperture means;

locking means carried by said casing and said pushbutton construction means to lock said lamp holder means in locked condition in said casing by an initial pushing in action of said lens holding means, followed by a releasing action of said lens holding means;

locking release means carried by said casing and said push-button construction means to release said lamp holder means from said locked condition by a pulling out action on said lens holding means followed by a releasing pushing in action of said lens holding means;

said lamp holder means having outwardly biased spring members defining part of said locking means and said casing having stop members defining part of said locking means to engage with said outwardly biased spring members to lock said lamp holder means to said casing; H

and means carried by said push-button construction means limiting movement of said lens holding means when being inserted in said casing and during said releasing pushing in action of said lens holding means.

26. In combination:

a tubular casing having a receiving casing aperture means adjacent one end;

a lens holding means and a lamp holder means relatively movably unitarily secured together to define a push-button construction means and being insertable in and removable from said casing through said aperture means, said push-button construction means being disposed in said aperture means;

locking means carried by said casing and said pushbutton construction means to lock said lamp holder means in locked condition in said casing by an initial pushing in action of said lens holding means, followed by a releasing action of said lens holding means;

locking release means carried by said casing and said push-button construction means to release said lamp holder means from said locked condition by a pulling out action on said lens holding means followed by a releasing pushing in action of said lens holding means;

said lamp holder means having outwardly biased spring members defining part of said locking means and said casing having stop members defining part of said locking means to engage with said outwardly biased spring members to lock said lamp holder means to said casing;

and means carried by said push-button construction means limiting movement of said lens holding means when being inserted in said casing and during said releasing pushing in action of said lens holding means, said means limiting movement of said lens holding means comprising a stop member positioned between said lens holding means and said lamp holder means.

27. A combination according to claim 25 in which said means limiting movement of said lens holding means is a stop member positioned in said lamp holder means.

28. In combination:

a tubular casing having a receiving casing aperture means adjacent one end;

a lens holding means and a lamp holder means relatively movably unitarily secured together to define a push-button construction means and being insertable in and removable from said casing through said aperture means, said push-button construction means being disposed in said aperture means;

locking means carried by said casing and said pushbutton construction means to lock said lamp means in locked condition in said casing by an initial pushing in action of said lens holding means, followed by a releasing action of said lens holding means;

locking release means carried by said casing and said push-button construction means to release said lamp holder means from said locked condition by a pulling out action on said lens holding means followed by a releasing pushing in action of said lens holding means;

said lamp holder means having outwardly biased spring members defining part of said locking means and said casing having stop members defining part of said locking means to engage with said outwardly biased spring members to lock said lamp holder means to said casing;

and means carried by said push-button construction means limiting movement of said lens holding means when being inserted in said casing and during said releasing pushing in action of said lens holding means;

said lens holding means having outer connecting and moving frame members which define part of said locking release means and inwardly hold said outwardly biased spring members to allow said outwardly biased spring members to pass upwardly past said stop members after said releasing pushing in action has been made on said lens holding means.

29. A combination according to claim 28 in which said means limiting movement of said lens holding means is a stop member slidably positioned on at least one of said moving frame members.

30. A combination according to claim 28 in which said outwardly biased spring members are each made from a single spring wire.

31. A combination according to claim 30 in which said single spring wire is bent to form a pair of downward U-shaped legs connected together by a horizontal spring member, said legs and horizontal spring member being resiliently horizontally movable together and having a normal unbiased position outwardly beyond said casing, said U-shaped legs having double slant portions which are moved inwardly when said lamp holder means is pushed into said casing, and in which said outer connecting frame members of said lens holding means are engageable with said horizontal spring members during said releasing pushing in action of said lens holding means to displace said horizontal spring members from said stop members during said releasing pushing in action of said lens holding means to prevent said horizontal spring members from remaining locked to said casing during said releasing pushing in action of said lens holding means.

32. In combination:

a tubular casing having a receiving casing aperture means adjacent one end;

a lens holding means and a lamp holder means relatively unitarily secured together to define a pushbutton construction means and being insertable in and removable from said casing through said aperture means, said push-button construction means being disposed in said aperture means;

locking means carried by said casing and said pushbutton construction means to lock said lamp holder means in locked condition in said casing by an initial pushing in action of said lens holding means, followed by a releasing action of said lens holding means;

locking release means carried by said casing and said push-button construction means to release said lamp holder means from said locked condition by a pulling out action on said lens holding means followed by a releasing pushing in action of said lens holding means;

and said lamp holder means having outwardly biased spring members defining part of said locking means and said casing having stop members defining part of said locking means to engage with said outwardly biased spring members to lock said lamp holder means to said casing.

33. In combination:

a tubular casing having a receiving casing aperture means adjacent one end;

a lens holding means and a lamp holder means relatively unitarily secured together to define a push-button construction means and being insertable in and removable from said casing through said aperture means, said push-button construction means being disposed in said aperture means;

locking means carried by said casing and said pushbutton construction means to lock said lamp holder means in locked condition in said casing by an initial pushing in action of said lens holding means, followed by a releasing action of said lens holding means;

locking release means carried by said casing and said push-button construction means to release said lamp holder means from said locked condition by a pulling out action on said lens holding means followed by a releasing pushing in action of said lens holding means;

and said lamp holder means having outwardly biased spring members defining part of said locking means and said casing having stop members defining part of said locking means to engage with said outwardly biased spring members to lock said lamp holder means to said casing;

said lens holding means having outer connecting and moving frame members which define part of said locking release means and inwardly hold said outwardly biased spring members to allow said outsingle spring wire is bent to form a pair of downward U- shaped legs connected together by a horizontal spring member, said legs and horizontal spring member being resiliently horizontally movable together and having a normal unbiased position outwardly beyond said casing,

said U-shaped legs having double slant portions which are moved inwardly when said lamp holder means is pushed into said casing, and in which said outer connecting frame members of said lens holding means are engageable with said horizontal spring members during said releasing pushing in action of said lens holding means to displace said horizontal spring members from said stop members during said releasing pushing in action of said lens holding means to prevent said horizontal spring members from remaining locked to said casing during said releasing pushing in action of said lens holding means.

References Cited UNITED STATES PATENTS 2,904,662 9/ 1959 Spring.

3,090,949 5/ 1963 Hallerberg 200159 3,197,598 7/1965 Andersen et al.

3,249,705 5/1966 Amis et al.

3,267,245 8/ 1966 Vincent.

3,274,354 9/1966 Stevens.

HERMAN O. JONES, Primar Examiner 

